Knee protection device having a load distributor for a motor vehicle

ABSTRACT

A knee protection device in a motor vehicle having a dimensionally stable, cushioned and essentially plate-shaped load distributor which is supported on the end side by curved deformable holders on a cross member fixed to the vehicle. The energy absorption capacity of the two holders is fully utilized by spanning a reinforcement on the back side of the load distributor. The reinforcement has an approximately hat-shaped cross-section, extends at least near the holders and has outwardly projecting flanges which are connected with the load distributor.

BACKGROUND AND SUMMARY OF THE INVENTION

This invention relates to a knee protection device in a motor vehiclehaving a dimensionally stable, cushioned and essentially plate-shapedload distributor which is supported on the end side by way of curveddeformable holders on a vehicle-fixed cross member.

A knee protection device of this type, in the case of which the holdersdeform during a knee impact on the load distributor while absorbingenergy, is known from Tomita et al., U.S. Pat. No. 4,978,136. The loaddistributor must have a stiff construction so that the holders deform intheir constructively predetermined direction which yields a maximumenergy absorption. In order to achieve this dimensional stability of theload distributor, it is known to bend it and to provide it with beads.The endeavors to stiffen the load distributor by deforming measures arelimited so that it may happen that the energy absorption capacity of themembers cannot be fully exhausted because the load distributorexperiences a strong deformation.

It is an object of the invention to ensure by simple measures that also,in the case of a very high local stressing of the load distributor, itis not subjected to any deformation so that the energy absorptioncapacity of the holders supporting it can be fully exhausted.

This and other objects have been achieved according to the presentinvention by providing a knee protection device in a motor vehiclecomprising a dimensionally stable, cushioned and essentiallyplate-shaped load distributor; curved deformable holders supported on avehicle-fixed cross member, said holders being arranged and configuredto support respective lateral ends of said load distributor; and areinforcement connected to a rear side of the load distributor, saidreinforcement extending laterally to proximate said holders and havingan approximately hat-shaped cross-section comprising outwardlyprojecting flanges, said flanges being connected with said loaddistributor.

A particularly good integration of the holders is achieved when thereinforcement extends along the entire length of the load distributor.The reinforcement may be notched in the area of the holders in order toallow the holders to extend through the reinforcement.

In this connection, the introduction of force into the holders isfurther improved if the reinforcement is connected with the holders.

A targeted increase of the moment of resistance and thus a conducting offorce to a predetermined point is achieved by varying the profile widthand/or the profile height of the reinforcement along its longitudinalcourse. According to one preferred embodiment of the invention, theprofile height changes continuously so that the moment of resistanceincreases constantly in the direction of the larger profile height. Itwill then be possible, for example, based upon space availability, touse holders with a different deformation capacity and to act upon thesewith respect to force as the result of the required profile constructionof the reinforcement in such a manner that the maximally possibledeformation capacity is exhausted without any local failure of the kneeprotection device.

Preferred cross-sectional forms of the reinforcement are in this caseapproximately V-shaped, approximately U-shaped or approximatelysemicircular.

The object of the invention will be explained in the following inreference to a knee protection device assigned to the front passengerside of a motor vehicle.

Other objects, advantages and novel features of the present inventionwill become apparent from the following detailed description of theinvention when considered in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a reinforced load distributor accordingto a preferred embodiment of the present invention, which is supportedby two end-side holders in a fixed manner on the vehicle body;

FIGS. 2 to 4 are respective sectional views along the Line II--II inFIG. 1 with different cross-sectional shapes of the reinforcement.

DETAILED DESCRIPTION OF THE DRAWINGS

A knee protection device 1, which, on the front passenger side, isassigned to a dashboard in a motor vehicle which is not shown, comprisesa dimensionally stable, plate-shaped load distributor 3. The loaddistributor 3 is stiffened by impressed longitudinal beads 2, and issupported at its lateral end areas by respective curved holders 4, whichare deformable in a targeted manner, and are fixed on a cross member 5of the vehicle body.

The load distributor 3 is cushioned on its front side 6 (generallyfacing toward the rear of the motor vehicle) in a manner which is notshown. On the rear side (generally facing toward the front of the motorvehicle) of the load distributor 3 a reinforcement 7 is disposed whichhas an approximately hat-shaped cross-section and which, in theillustrated embodiment, extends near the holders 4. The reinforcement 7is fixedly connected with the load distributor 3 by means of its flanges8 projecting to the outside. However, it is also contemplated to extendthe reinforcement to the holders 4 or past the holders 4 and to connectthe reinforcement to the holders, whereby a particularly advantageousintroduction of force into the holders 4 is achieved in the case of aknee impact. The reinforcement 7 may be connected to the holders 4 bywelding, by brackets, or in other known ways.

The holders 4 of the same device may have different deformationcapacities with different response thresholds because of the maximallypossible dimensioning and/or alignment, due to space limitations. Insuch a case, when a load is applied, the energy absorption capacity ofone holder 4 may be almost exhausted at the same time that thedeformation of the other holder 4 has not yet started. In order toeffectively deal with this circumstance when such a condition exists,the cross-sectional shape of the reinforcement 7 placed on the rear sideof the load distributor 3 is varied in a targeted manner. In particular,the profile height is increased constantly along the longitudinal lengthof the reinforcement in a direction toward the holder 4 which has ahigher energy absorption capacity. With an increasing profile height,the moment of resistance will also increase so that in this manner alarger force potential can be introduced into the assignedhigher-stressable holder and both holders 4 are therefore uniformlydeformed while absorbing energy.

In this case, the design of the cross-section of the reinforcement 7which is generally approximately hat-shaped, can be changed within widelimits, in which case cross-sectional forms having an approximatelyV-shape as shown in FIG. 2, an approximately U-shape, as shown in FIG.3, or an approximately semicircular form, as shown in FIG. 4.

Although the invention has been described and illustrated in detail, itis to be clearly understood that the same is by way of illustration andexample, and is not to be taken by way of limitation. The spirit andscope of the present invention are to be limited only by the terms ofthe appended claims.

What is claimed is:
 1. Knee protection device in a motor vehiclecomprising:a dimensionally stable, cushioned and essentiallyplate-shaped load distributor; curved deformable holders supported on avehicle-fixed cross member, said holders being arranged and configuredto support respective lateral ends of said load distributor; and areinforcement connected to a rear side of the load distributor, saidreinforcement extending laterally to proximate said holders and havingan approximately hat-shaped cross-section comprising outwardlyprojecting flanges, said flanges being connected with said loaddistributor.
 2. Knee protection device according to claim 1, wherein thereinforcement extends along an entire length of the load distributor. 3.Knee protection device according to claim 2, wherein the reinforcementis notched to allow the holders to extend through the reinforcement. 4.Knee protection device according to claim 2, wherein the reinforcementis connected with the holders.
 5. Knee protection device according toclaim 3, wherein the reinforcement is connected with the holders. 6.Knee protection device according to claim 1, wherein at least one of aprofile width and a profile height of the reinforcement changes along alongitudinal course of the reinforcement.
 7. Knee protection deviceaccording to claim 2, wherein at least one of a profile width and aprofile height of the reinforcement changes along a longitudinal courseof the reinforcement.
 8. Knee protection device according to claim 4,wherein at least one of a profile width and a profile height of thereinforcement changes along a longitudinal course of the reinforcement.9. Knee protection device according to claim 6, wherein said profileheight changes continuously along said longitudinal course.
 10. Kneeprotection device according to claim 7, wherein said profile heightchanges continuously along said longitudinal course.
 11. Knee protectiondevice according to claim 8, wherein said profile height changescontinuously along said longitudinal course.
 12. Knee protection deviceaccording to claim 1, wherein the cross-section of the reinforcement isapproximately V-shaped.
 13. Knee protection device according to claim 1,wherein the cross-section of the reinforcement is approximatelyU-shaped.
 14. Knee protection device according to claim 1, wherein thecross-section of the reinforcement is approximately semicircular.